There is a thing called mass and usually as a soldier you think you have a bit too much on you. It can range from a 20 litter load of water to a 120 kg of a leaking friend and more. It is important to note how different locations on your body changes the way you feel and move with it. Fore example if you are walking with boots in the mud you will fee a lot of tension in the hips pulling you out and moving all the extra mass on your boots and if you had the same mass on your back you would feel much lighter and able to move. Consider this idea and play with it in your work to make life less stressful and free. Consider also the workability of the situation. Sometimes we need the handgun on the hip rather than on the pack or chest.